Do something to selected image in scroll view - iphone

Question

I try to make following: Horizontal list of images, that I can select and do something with it. For example flip image around x axis. I know how to rotate image. I created scrollview and load it with images. I added event handler when I tap on image. But I don't know how to do something with tapped image. How to code method to do something with tapped image?
- (void)viewDidLoad {
[super viewDidLoad];
img1 = [UIImage imageNamed:#"imgTest.jpg"];
img2 = [UIImage imageNamed:#"imgTest2.jpg"];
arrayOfImages = [[NSMutableArray alloc] init];
[arrayOfImages addObject:img1];
[arrayOfImages addObject:img2];
[arrayOfImages addObject:img1];
[arrayOfImages addObject:img2];
scrollView = [[UIScrollView alloc] init];
scrollView.scrollEnabled = YES;
scrollView.pagingEnabled = YES;
scrollView.directionalLockEnabled = YES;
scrollView.showsVerticalScrollIndicator = NO;
scrollView.showsHorizontalScrollIndicator = NO;
scrollView.delegate = self;
scrollView.backgroundColor = [UIColor blueColor];
scrollView.autoresizesSubviews = YES;
scrollView.frame = CGRectMake(0, 0, 320, 128);
[self.view addSubview:scrollView];
UIImage *imageToAdd;
int x = 0;
int y = 0;
for(imageToAdd in arrayOfImages)
{
UIImageView *temp = [[UIImageView alloc] initWithImage:imageToAdd];
temp.frame = CGRectMake(x, y, 128, 128);
temp.userInteractionEnabled = YES;
x += 135;
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imageTapped:)];
[temp addGestureRecognizer:tap];
[scrollView addSubview:temp];
}
...
- (void)imageTapped:(UIGestureRecognizer *)sender
{
// how to get reference on selected item in scrollview???
}

Answer 1

A gesture recognizer has a view property that returns the view associated with the recognizer. Since you know that it'll be a UIImageView you can simply cast it and use it as in:
UIImageView *iv = (UIImageView *)[sender view];
And your image can then be queried via:
UIImage *image = [iv image];
If you need to know the index in your array, there are two ways: either simply use [arrayOfImages indexOfObject:image];, or you can assign tags (numbers) to views and use them. A tag is not used by Apple, it's only here so we developers can "mark" views in some way. For example:
NSInteger counter = 0;
for(imageToAdd in arrayOfImages)
{
UIImageView *temp = [[UIImageView alloc] initWithImage:imageToAdd];
count.tag = counter++;
...
}
Then, in your imageTapped:, you can query the index via tag:
NSInteger index = [imageView tag];